education/kstars/README.ephemerides

0001 KStars keeps track of thousands of comets and asteroids.
0002 It uses orbital data published by NASA's Jet Propulsion
0003 Laboratory (JPL); these data are known as "orbital elements".
0004 Because these small bodies are easily perturbed as they
0005 wander about the solar system, their orbital elements must
0006 be updated regularly.  Updating the elements will also add
0007 any recently-discovered bodies.
0008
0009
0010 How to update the orbital elements of comets and asteroids:
0011
0012 -=( 1 )=-  The Easy Way.
0013
0014 Start KStars, then open the "Get New Stuff" Tool by selecting
0015 "Download Data..." from the File menu, or by pressing Ctrl+D.
0016
0017 If a new "ephemerides" package is available, select it and press
0018 the Install button.  Voila!
0019
0020 If the "ephemerides" package available from the "Get New Stuff"
0021 Tool is too old, you can use the menu items under
0022 "Settings" > "Updates" to download the last ephemerides from
0023 NASA's Jet Propulsion Laboratory website.
0024
0025
0026 -=( 2 )=-  Doing it Manually.
0027
0028 It is possible that the ephemerides package is not completely
0029 up-to-date.  Fortunately, it's relatively simple to update the
0030 files manually whenever you want.
0031
0032 ::NOTE:: If you find that the ephemerides package is woefully
0033 outdated, and you follow this manual-install procedure, PLEASE
0034 send your final comets.dat and asteroids.dat files to
0035 kstars-devel@kde.org!  Now is your chance to be a KStars Hero!
0036
0037
0038 Step 1: The Comets
0039
0040 You can use the following command to download comets.dat file
0041 from JPL website :
0042 wget -O comets.dat --post-data="obj_group=all&obj_kind=com&obj_numbered=all&OBJ_field=0&OBJ_op=0&OBJ_value=&ORB_field=0&ORB_op=0&ORB_value=&combine_mode=AND&c1_group=OBJ&c1_item=Af&c1_op=!%3D&c1_value=D&c2_group=OBJ&c2_item=Ae&c2_op=!%3D&c2_value=SOHO&c_fields=AcBdBiBgBjBlBkBqBbAiAjAgAkAlApAqArAsBsBtCh&table_format=CSV&max_rows=10&format_option=full&query=Generate%20Table&.cgifields=format_option&.cgifields=field_list&.cgifields=obj_kind&.cgifields=obj_group&.cgifields=obj_numbered&.cgifields=combine_mode&.cgifields=ast_orbit_class&.cgifields=table_format&.cgifields=ORB_field_set&.cgifields=OBJ_field_set&.cgifields=preset_field_set&.cgifields=com_orbit_class" http://ssd.jpl.nasa.gov/sbdb_query.cgi
0043
0044 Delete or comment (with a '#') the first line.
0045
0046 Finally, copy your modified "comets.dat" to
0047 ~/.kde/share/apps/kstars/ (for a single-user install) or
0048 $KDEDIR/share/apps/kstars/ (for a system-wide install).
0049
0050
0051 Step 2: The Asteroids
0052
0053 You can use the following command to download asteroids.dat
0054 file from JPL website :
0055 wget -O asteroids.dat --post-data="obj_group=all&obj_kind=ast&obj_numbered=num&OBJ_field=0&ORB_field=0&c1_group=OBJ&c1_item=Ai&c1_op=%3C&c1_value=12&c_fields=AcBdBiBhBgBjBlBkBmBqBbAiAjAgAkAlApAqArAsBsBtCh&table_format=CSV&max_rows=10&format_option=full&query=Generate%20Table&.cgifields=format_option&.cgifields=field_list&.cgifields=obj_kind&.cgifields=obj_group&.cgifields=obj_numbered&.cgifields=combine_mode&.cgifields=ast_orbit_class&.cgifields=table_format&.cgifields=ORB_field_set&.cgifields=OBJ_field_set&.cgifields=preset_field_set&.cgifields=com_orbit_class" http://ssd.jpl.nasa.gov/sbdb_query.cgi
0056
0057 Delete or comment (with a '#') the first line.
0058
0059 Finally, copy your modified "asteroids.dat" to
0060 ~/.kde/share/apps/kstars/ (for a single-user install) or
0061 $KDEDIR/share/apps/kstars/ (for a system-wide install).
0062
0063
0064 -=( 3 )=-  Another way.
0065
0066 The last method is to point your browser to the following
0067 URL:
0068 http://ssd.jpl.nasa.gov/sbdb_query.cgi
0069 and generate the file using the form
0070
0071 You must select the following columns to make the file
0072 compatible with kstars :
0073
0074 - for comets
0075 1 full name
0076 2 modified julian day of orbital elements
0077 3 perihelion distance
0078 4 eccentricity of orbit
0079 5 inclination angle of orbit in degrees
0080 6 argument of perihelion in degrees
0081 7 longitude of the ascending node
0082 8 time of perihelion passage
0083 9 orbit solution ID
0084 10 absolute magnitude
0085 11 slope parameter
0086 12 Near-Earth Object (NEO) flag
0087 13 comet total magnitude parameter
0088 14 comet nuclear magnitude parameter
0089 15 object diameter
0090 16 object bi/tri-axial ellipsoid dimensions
0091 17 geometric albedo
0092 18 rotation period
0093 19 orbital period
0094 20 earth minimum orbit intersection distance
0095 21 orbit classification
0096
0097 -for asteroids
0098 1 full name
0099 2 Modified Julian Day of orbital elements
0100 3 perihelion distance
0101 4 semi-major axis
0102 5 eccentricity of orbit
0103 6 inclination angle of orbit in degrees
0104 7 argument of perihelion in degrees
0105 8 longitude of the ascending node in degrees
0106 9 mean anomaly
0107 10 time of perihelion passage
0108 11 orbit solution ID
0109 12 absolute magnitude
0110 13 slope parameter
0111 14 Near-Earth Object (NEO) flag
0112 15 comet total magnitude parameter
0113 16 comet nuclear magnitude parameter
0114 17 object diameter
0115 18 object bi/tri-axial ellipsoid dimensions
0116 19 geometric albedo
0117 20 rotation period
0118 21 orbital period
0119 22 earth minimum orbit intersection distance
0120 23 orbit classification
0121
0122 The advantage of this method is that you can play with
0123 several filters and get a file containing exactly what
0124 you want.
0125
0126 Don't forget to delete or comment (with a '#') the first
0127 line.
0128
0129 Finally, copy your files to
0130 ~/.kde/share/apps/kstars/ (for a single-user install) or
0131 $KDEDIR/share/apps/kstars/ (for a system-wide install).